Cadillac DeVille
18.5 MPG The 2005 Cadillac DeVille is EPA-rated at 18.5 MPG combined (15.5 city / 23 highway). Over 15,000 miles a year that is about 811 gallons, $2595 a year in fuel, or $0.173 per mile at $3.20/gal.
Across its full 1988–2005 run it averages 18.3 MPG, improving by 1.5 MPG over 11 model years.
Running cost at different fuel prices and mileages
The figure everyone actually wants, and the one the EPA does not publish — because it depends on a fuel price no agency will commit to.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.135 | $1351 | $2027 | $2703 |
| $3.00/gal | $0.162 | $1622 | $2432 | $3243 |
| $3.20/gal | $0.173 | $1730 | $2595 | $3459 |
| $3.50/gal | $0.189 | $1892 | $2838 | $3784 |
| $4.00/gal | $0.216 | $2162 | $3243 | $4324 |
| $4.50/gal | $0.243 | $2432 | $3649 | $4865 |
| $5.00/gal | $0.270 | $2703 | $4054 | $5405 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2005 | 18.5 MPG | 15.5 | 23 | $3375 | 481 | 2 |
| 2004 | 19 MPG | 16 | 24 | $3300 | 468 | 2 |
| 2003 | 19 MPG | 16 | 25 | $3300 | 468 | 1 |
| 2002 | 19 MPG | 16 | 25 | $3300 | 468 | 1 |
| 2001 | 18 MPG | 15 | 25 | $4300 | 494 | 1 |
| 2000 | 19 MPG | 15 | 25 | $4050 | 468 | 1 |
| 1999 | 18 MPG | 15 | 24 | $4300 | 494 | 1 |
| 1998 | 18 MPG | 15 | 24 | $3450 | 494 | 1 |
| 1997 | 18 MPG | 15 | 24 | $4300 | 494 | 1 |
| 1996 | 18 MPG | 15 | 24 | $4300 | 494 | 1 |
| 1988 | 17 MPG | 15 | 22 | $3650 | 523 | 1 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
How it compares in its class
Among the 149 large cars models tracked here, the Cadillac DeVille ranks 96 on current figures, against a class average of 21.6 MPG.
Closest more-efficient alternatives in the same class: BMW 550i Gran Turismo (19), BMW 750i xDrive (19), BMW 750Li (19), BMW 750Li xDrive (19), BMW Alpina B7 LWB (19).
Tailpipe CO₂ is rated at 481 grams per mile, which works out to roughly 7.2 tonnes a year at 15,000 miles.
Questions
What MPG does the Cadillac DeVille get?
The 2005 Cadillac DeVille is rated at 18.5 MPG combined by the EPA — 15.5 city and 23 highway. Across all 11 model years in the database it averages 18.3 MPG, ranging from 17 to 19 depending on year and trim.
How much does a Cadillac DeVille cost in fuel per year?
At 18.5 MPG and 15,000 miles a year, it burns about 811 gallons — roughly $2595 a year with fuel at $3.20 a gallon, or $0.173 per mile. The EPA's own published annual figure for the 2005 model is $3375.
Has the Cadillac DeVille become more efficient over time?
Yes. It has gone from 17 MPG in 1988 to 18.5 in 2005 — an improvement of 1.5 MPG, or 9% across 11 model years.
Is the Cadillac DeVille efficient for its class?
It ranks 96 of 149 in the Large Cars class on current figures, against a class average of 21.6 MPG. That is 3.1 worse than typical for the class.
EPA test figures from fueleconomy.gov. Cost per mile and annual fuel spend are computed at a reference price of $3.20 per gallon — use your own price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.